Should have been clearer ... When I sent my Spoiler electronics to Alembic for customization, I should have declared the goods for export. When the goods were returned, there was no export declaration, so they were considered newly imported, and I had to pay taxes. (They don't seem to realize that greed is one of the capital sins.)
Anyway, as far as I know they do check pretty much everything, and your parcel just happened to be in a lot that took a lot of time to process.